I think the time has come for a straightforward case, which provides a pretty simple situation, and requires judgement based upon fairly well known facts.
Antonius of Verditius and Gorax of Tytalus had long engaged in a bitter argument, which despite the peacemaking attempts of their sodales escalated to Wizard's War. The two magi lived in covenants a mere hundred miles apart, within the Roman Tribunal. When the war was declared everyone expected Antonius to win; he was a puissant weaponsmith, and maker of fine machineries of destruction. Yet mere minutes after the opening of hostilities, while Antonius was still within his Sanctum, Gorax walked in to his enemies covenant, and collapsed the tower that contained Antonius' sanctum and forge upon him, killing him outright.
Immediately afterwards, Gorax was killed by three magi of this covenant, Clara of Verditius performing the killing blow with a mechanical wyvern, but Heironymous attacking him with a Pit of the Gaping Earth wand and and Valeria also attacking Gorax indirectly by a CreoAquam enchantment that flooded the pit in to which he fell (He may possibly have drowned while incapacitated by the Wyvern attack?) . The three claim that they killed Gorax in the act of committing a Hermetic crime, and that as the collapse of the tower denied them a perfectly usable lab, the flames from the smashed forge caused a fire that endangered the library, and three grogs armed with covenant magic weapons were also killed in the collapse, forfeit immunity applies and they killed Gorax when he was not under the protection of the Code, that is while he was committing a Hermetic Crime, and therefore no charges can be brought against them.
Gorax's covenant strongly disagrees, and demand justice for Gorax. None fo the other three had declared Wizard's War, and no retribution they say should have fallen upon their sodalus for pursuing a legitimately declared war - so they are clearly guilty.
Over to you